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Re: [PATCH] Fold zero extensions into bit-wise ANDs

From: Jan Hubicka <jh at suse dot cz>
To: Segher Boessenkool <segher at chello dot nl>
Cc: Roger Sayle <roger at eyesopen dot com>,Linus Torvalds <torvalds at transmeta dot com>, gcc-patches at gcc dot gnu dot org
Date: Wed, 17 Apr 2002 18:03:52 +0200
Subject: Re: [PATCH] Fold zero extensions into bit-wise ANDs
References: <Pine.LNX.4.33.0204162341450.7849-100000@www.eyesopen.com> <3CBD9A87.1F6E8FE7@chello.nl>

> you have a zero extension from 8 to 64 bit, which explains the xorl.
> 
> To get GCC to do this, you need a sign-extend of a zero-extend to be
> optimized to the equivalent zero-extend.  It looks like it doesn't
> know how to do that, yet.

This really should trigger in combine, as it contains code to do the
trick.

Honza
> 
> 
> Segher

Follow-Ups:
- Re: [PATCH] Fold zero extensions into bit-wise ANDs
  - From: Segher Boessenkool

References:
- Re: [PATCH] Fold zero extensions into bit-wise ANDs
  - From: Roger Sayle
- Re: [PATCH] Fold zero extensions into bit-wise ANDs
  - From: Segher Boessenkool

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